This invention relates to a key manufacturing machine. The key manufacturing machine utilizes a conventional drilling means which is adapted to facilitate drilling operation thereof. Conventionally, the key manufacturing machine has a rotating means therein for receiving other components so that a key can be suitably supported and positioned for machining or drilling. The rotating means utilized at the present time has a top end portion thereof which is provided circumferentially with a plurality of studs protruding upward in different height. When a desired height of the stud or configuration of all studs is required, a changeover of respective stud is performed. In order to machine a key more efficiently or to obtain a semi-automatic machining operation of a key, the present invention has improved the rotating means to be adjustable and pre-settable and further incorporates a sensing device therein.